Ok Im not necessarily accusing Bob Kirkland of being Red John, but unless the writers actually believe Red John has powers(which ruins the charm of the show), he is the only one who could access what Jane was doing in his room(other than Patrick ofc), even though Jane might have tricked him (the toothpick thing). 

Now it could also be Haffner, Visualize has powers and insight into a lot of organizations, why not the CBI? He couldve also accessed what PJ was doing. Similalry it could be Stiles. 

But neither of them could access Patricks brain( though idk cause Stiles does seem to have powers) and pull out his childhood memory. So again pointing towards PJ. The only reason Im not accusing PJ is I wont be able to stand it if he is RJ. But all the clues point towards him.

Now on the others on the list
Partridge - creep, works for the CBI, but then why would he need a mole within the CBI?
I couldnt even remember who the sheriff was so it would be extremely disappointing if Heller has him as RJ and most of the audience cant even relate.

Now Bertram is interesting. maybe Lisbon is one of his accomplices and is smarter than we all think? Maybe she is feeding him with info.

Finally Reede Smith has appeared on one episode(like the sheriff). again highly unlikely only clue is when he actively participates in the red pearl job the patrick pulls

Alright. We now have a list of seven suspects. Let me reduce it to 5:

Gale Bertram: Not 100% sure he isnt Red John, but look at it this way:
Red John would not lose at poker. And if he did, he wouldnt accept Patricks help. 
Pointing towards him is of course the assassin with the rope in his room.

But now to Robert Kirkland: He, I am 100% sure is not Red John. 
He steals Patrick Janes stuff AFTER Lorelei is dead. So Red John knew the list before the break-in. He wouldnt have had to take this risk and send HomelandSecurity Agents to steal the stuff. They might ask questions. No, Kirkland is after Red John himself. Red John must have a lot of friends but also a lot of enemies. Kirkland is his enemy. He wants to hunt down Red John and steals Patricks stuff to do so. 

I really dislike the theory that Partick is Red john, i think it will loose the point of the plot of the drama, its nice to have faith that Patrick could actually be the only one that can out smart red john. 

I also dislike the theory's on that it is the main characters. 

Wayne Rigsby - I think the way He acts in most of the episodes, is proof that he's not red john, he is a bit too clumsy, and makes allot of mistakes, while i think red john is a bit more careful and meticulous 

Cho - I don't think its cho, He looks so small to fit into the 6" guideline and also, we are also lead to believe that red john is a white man, so this could rule cho out. 

Lisbon + Grace - While many people think that red john could be in fact, a girl, we are lead to believe that  red john raped Miranda before he killed her and the silhouette we see of red john in episodes, is defiantly not womanly, Just because Lisbon is so interested in what Patrick is up to doesn't mean she is a killer, i mean wouldn't anyone want to know what he was thinking about red john? i certainly would! 

While i do think Brett partridge could be a likely suspect to be red john, there are a few reasons why i think this could not be plausible. 

1) He shows an active dislike for Patrick  don't you think red john would be a bit more clever, than going shouting  his mouth of about how he actively dislikes him? 

2) Whenever he's at a crime scene, he is always trying to persuade Patrick that it was red john who committed the murder, when it turns out that it was not red john who did it, or trying to convince Patrick it was red john, when it wasn't, i think red john would be a bit more clever,  Trying to throw Patrick off guard that way, its a bit of an half-hearted attempt isn't it? 

3) He's a bit too easy to find, he works at the CBI in the forensics, while this would explain why no DNA or evidence if ever found leading to red john, (because he knows what he's doing) he's a bit too easy to find, and Lorelei wouldn't of treated it as,much of a task when seeking was him out, if he would be working at CBI in the morning. 

I think Brett Styles could be Red john, as he is good at manipulating people, shown when he nearly convinces grace to join visualize, He has the money and power, and could be quite hard to find when Lorelei was out to get him, as i could see him quite easily being able to disappear without a trace. Also whenever Patrick asks him for a favour, it always turns out in red johns advantage. He wanted Patrick to find kristia Fry, But however, Red john seemed to be angry that Lorelei told Patrick that He had met him. I think If it is not Brett Styles, Red john might of used to be a member of visualize  and may of admitted some things he regrets saying, in one of them one-to-one meetings they have at visualize to "clear their conscience", and scared Bret stiles into being one of his allies.

I also think there is a chance it could be Gale Bertram, Patrick had him as a suspect in the episode "strawberry's and cream", He obviously Has a bit of a dislike for him, and thinks he is capable of killing someone, while Patrick said in an earlier episode that brett styles "could not hurt a fly"